Exposé found its way into Mac OS X Panther as a nifty hack by one of the Apple engineers. Exposé was previewed and quickly added to Mac OS X's codebase as a must-have for the Panther release and has been retained in Tiger. Exposé uses Quartz rendering to quickly give you access to all of the open windows for running applications, or to scoot them out of the way so you can quickly see what's on your Desktop.
Exposé can be activated in three ways:
By default, F9 tiles all open windows (as shown in Figure 9-1), F10 tiles all open windows of the current application, and F11 forces all open windows out of the way so you can see what's on the Desktop. In each case, pressing the given function key a second time reverses the effect of pressing it the first time. For example, if you press F11 to hide all open windows, pressing F11 again will undo this action and return all open windows to the Desktop.
Other tricks you can try with Exposé include:
If you hold down the Shift key and press either of the F9, F10, or F11 keys, Exposé works in slow motion.
If you've pressed F9 to separate the windows (as shown in Figure 9-1), you can use the arrow keys on your keyboard to highlight a particular window. The window is shaded light blue, and its filename is superimposed on the window.
If you've pressed F10 to separate the windows for the current application, hit the Tab key to switch to another application and bring its windows again, separated by Exposé to the front. Also, Shift-Tab cycles backward through the window stack, so if you've gone too far with the Tab key, try hitting Shift-Tab to return to the application you need.
Figure 9-1. An Exposé-tiled desktop
If you've done the last trick, combine that with the previous and use the arrow keys to highlight a window; pressing Return brings that window to the front of the stack.
If you've used F11 to push the windows out of the way so you can see the Desktop, the window that previously had the focus is still active, even though it isn't really visible. For example, if you have a Terminal window open and you hit F11, try issuing a simple command like ls, then hit F11 to bring the windows back; you should see the output of ls in the Terminal window. (F9 and F10 take the focus away.)